The invention relates generally to data networks and more specifically to a technique for reducing power consumption in a network device.
As networking has become more popular and users demand higher bandwidth, existing communication networks are adapted to facilitate data transmission. For example, telephone modems were applied to telephone lines to allow the public switched telephone network to support data transmission. Likewise, cable television networks have been adapted to allow the use of cable modems for data communication at higher data rates than those afforded by traditional telephone modems. While cable modems have been offered as stand-alone desktop devices, there is a desire to be able to integrate cable modems into products such as desktop and portable computers, set-top boxes, and video equipment. However, high power demands of current cable modems result in high heat dissipation and impede efforts to miniaturize cable modems and integrate them into other products. The bulkiness, high power demands, and high heat dissipation prevent cable modems from being integrated into other products that would benefit from being connected to a network, for example, power, gas, and electric meters, security systems, and household appliances.
Technologies are also being developed to allow telephone communications over cable television networks. However, telephone communications can be essential in emergencies and thus need to be very reliable. Battery backup systems can be used to power a cable modem used for providing telephone communications. Unfortunately, because of the high power demands of current cable modems, such battery backup systems would either require very large and heavy batteries or would offer only a very short amount of backup time.
Because of the data speeds and communication frequencies used by cable modems, such modems inherently tend to draw large amounts of power. Thus, a cable modem cannot be easily redesigned using conventional techniques to reduce power consumption. Techniques for reducing power consumption in cable modems tend to require use of expensive components, and heat dissipation problems require costly and bulky heatsinks and fans.
Attempts have been made to reduce power consumption of cable modems by placing them in a quiescent mode, but such attempts have failed because of the long period of time required to reactivate the cable modem from the quiescent mode. Thus, cable modems have had to be maintained in an active receive mode continuously, consuming large amounts of power. Thus, a technique is needed to reduce the power consumption of a cable modem.